With the development of science and technology, the quality and function of the display screen of the electronic products have been improved continually, and the application scope of the display screen has become wider and wider. Currently, the display screens of the electronic products mainly are mainly divided into two categories: liquid crystal display screens and OLED display screens. Taking the liquid crystal display screen for example, a touch panel or a transparent glass cover plate in the liquid crystal display screen can be affixed to the LCD module in two methods of a full lamination method and an edge lamination method. The edge lamination method refers to bonding the touch panel or the transparent glass cover plate along the peripheral area of the LCD module through adhesive (also known as frame adhesive); while the full lamination method refers to bonding the touch panel or the transparent glass cover plate with the entire LCD module through an optical clear adhesive (OCA) or an optical clear resin (OCR). Compared to the edge lamination method, the lamination structure with better optical properties of light transmittance, color saturation etc. can be obtained in the full lamination method. Therefore, the market share of the liquid crystal display bonding in the full lamination method continues to increase.
The full lamination method includes: coating an OCA or an OCR on the touch panel or the transparent glass cover plate, and pre-curing the OCA or OCR firstly; then bonding the touch panel or the transparent glass cover plate with the liquid crystal substrate, and irradiating for curing through UV rays.
FIG. 1 is a schematic diagram of surface curing and side curing which are carried on in a full lamination method for bonding in the display panel. As shown in FIG. 1, the liquid crystal touch screen is formed by bonding the touch control panel 4 with the liquid crystal substrate 5 through the adhesive layer 2, and the opaque black matrix 6 is arranged in the non-display area. The black matrix 6 plays roles of shading metal lines, defining the display area and decorating etc. However, as the black matrix 6 is opaque, it will influence the irradiating curing effect of UV rays on the OCA or the OCR, and leads to the phenomenon of lacking of adhesive or adhesive remaining at the edge of the touch control display screen, and then the appearance of the touch control display screen is influenced, the mura phenomenon occurs when the touch screen is in operation (for example, a finger touches the touch screen), thus the user experience is greatly affected.
In order to overcome the above problems, one current solution includes, as shown in FIG. 1, surface curing the OCA or the OCR by a surface curing light source 7 firstly and then side curing the OCA or the OCR by a side curing light source 8, so the curing rate of the OCA or the OCR is improved. However, this method not only increases the process operations, but also the side curing is difficult to operate and the curing effect is also unsatisfactory.
In addition, the liquid crystal substrate 5 is usually fixed within a frame (not shown) through an adhesive component such as an adhesive tape. When the height of the frame is higher than the thickness of the liquid crystal substrate 5, the light leakage of the liquid crystal substrate 5 can be avoided. However, the difficulty of side curing the OCA or the OCR is increased. If the height of the frame is decreased, the side curing will become easier, but the risk of the light leakage of the liquid crystal substrate 5 is increased.
Therefore, it is necessary to design a display panel, for which side curing is not necessary for the OCA or the OCR when the full lamination method is used for bonding in the display panel, and at the same time the irradiating curing effect is guaranteed, the difficulty of irradiating curing is reduced, the process operations is simplified and the risk of the light leakage of the liquid crystal substrate is reduced.